JP2020512590A - Multi-channel signal coding method, multi-channel signal decoding method, encoder, and decoder - Google Patents

Abstract

A multi-channel signal encoding method, a multi-channel signal decoding method, an encoder, and a decoder are provided. The encoding method is a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, determining the initial reverberation gain parameter of the first channel signal and the second channel signal, the first The target reverberation of the first channel signal and the second channel signal based on the correlation between the channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter. Determining a gain parameter, quantizing the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter, the quantized first channel signal and the quantized first channel signal. Writing the two channel signals to the bitstream. The quality of the channel signal obtained after the reverberation process can be improved by the encoding method, the decoding method, the encoder and the decoder.

Description

  This application is filed with the Chinese Patent Office on March 31, 2017, which is hereby incorporated by reference in its entirety, entitled "Multi-Channel Signal Encoding Method, Multi-Channel Signal Decoding Method, Encoder, and Decoder Claim the priority of Chinese Patent Application No. 201710205821.2.

  This application relates to the field of speech coding, and more specifically to a multi-channel signal coding method, a multi-channel signal decoding method, an encoder, and a decoder.

  As the quality of life improves, people increase the demand for high quality audio. Compared to monophonic speech, stereophonic speech provides a sense of direction and a sense of distribution for each sound source, as well as improving clarity, intelligibility, and in-situ perception of sound. Therefore, stereo sound is very popular.

  The stereo processing technique mainly includes mid / side (Mid / Sid, MS) coding, intensity stereo (IS) coding, parametric stereo (Parametric Stereo, PS) coding, and the like.

  In the prior art, when coding a channel signal using PS coding, the encoder side performs spatial parameter analysis on the multiple channel signals to determine reverberation gain parameters and other spatial parameters of the multiple channel signals. , While encoding the reverberation gain parameter and other spatial parameters of the multiple channel signals, so that the decoder side, based on the reverberation gain parameter of the channel signal during decoding, decodes to improve the hearing effect. The reverberation processing of a plurality of channel signals obtained by the conversion can be executed. However, in some cases, for example, when the correlation between the channel signals is relatively low, reverberation processing is performed on the channel signals obtained by decoding based on the reverberation gain parameter corresponding to the channel signals. Cause a worse hearing effect.

  This application provides a multi-channel signal coding method, a multi-channel signal decoding method, an encoder, and a decoder for improving the quality of a channel signal.

  According to a first aspect, there is provided a multi-channel signal encoding method, the method comprising a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, a first channel signal and a second channel signal. Determining the initial reverberation gain parameter of the channel signal, based on the correlation between the first channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter The step of determining the target reverberation gain parameter of the first channel signal and the second channel signal, and quantizing the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter. , A step of writing the quantized first channel signal and the quantized second channel signal to the bitstream. Including

  In this application, the correlation between the channel signal and the downmix signal is considered when the target reverberation gain parameter of the channel signal is determined. In this way, a better processing effect can be obtained when the reverberation processing is performed on the channel signal based on the target reverberation gain parameter, which improves the quality of the channel signal obtained after the reverberation processing.

  Optionally, the correlation between the first channel signal or the second channel signal and the downmix signal is between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal. Or may be determined based on the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmix signal.

  With respect to the first aspect, in some implementations of the first aspect, the first channel signal, the second channel signal, and the downmix signal are channel signals obtained after the normalization process.

  In connection with the first aspect, in some implementations of the first aspect, the correlation between the first channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, And the step of determining the target reverberation gain parameter of the first channel signal and the second channel signal based on the initial reverberation gain parameter, the correlation between the first channel signal and the downmix signal and the second channel signal. Determining a target damping coefficient based on the correlation between the signal and the downmix signal, and adjusting the initial reverberation gain parameter based on the target damping coefficient to obtain the target reverberation gain parameter.

  The initial reverberation gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmix signal by using the attenuation coefficient.

  The correlation between the first channel signal, the second channel signal, and the downmix signal can be conveniently measured by using the energy of the channel signal, that is, the energy of the channel signal and the downmix signal. The target damping coefficient can be conveniently determined by comparing the difference between the energy. Specifically, when the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal is relatively large (greater than a predetermined threshold value), the first The correlation between the channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal may be considered to be relatively weak. In this case, a relatively large target damping coefficient can be determined. However, if the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal is relatively small (less than a predetermined threshold), then the first channel signal and The correlation between the downmix signal and the correlation between the second channel signal and the downmix signal may be considered relatively weak. In this case, a relatively small target damping coefficient can be determined.

  The step of determining the target attenuation coefficient based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal comprises May be a step of calculating a target attenuation coefficient based on the correlation of, or a step of directly determining the preset attenuation coefficient as the target attenuation coefficient after the correlation between the channel signal and the downmix signal is considered. May be

  With respect to the first aspect, in some implementations of the first aspect, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and The step of determining the target attenuation coefficient based on the correlation between the mix signal and the correlation between the second channel signal and the downmix signal comprises the energy of the first channel signal in the plurality of frequency bins and the downmix signal. Between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins, and a step of determining a target attenuation coefficient based on the difference value. Including.

  The difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal is the difference of the first channel signal in the plurality of frequency bins. It can be conveniently determined by comparing the difference value between the energy and the energy of the downmix signal and the difference value between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. Yes, and the damping factor is further determined. Therefore, it is not necessary to compare the difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal in all frequency bands. .

  With respect to the first aspect, in some implementations of the first aspect, between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and the second in the plurality of frequency bins. The step of determining the difference value between the energy of the channel signal and the energy of the downmix signal is the step of determining the first difference value between the energy of the first channel signal and the energy of the downmix signal. And a first difference value is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, the second step Determining a second difference value between the energy of the channel signal and the energy of the downmix signal, the second difference value being a plurality of frequencies. Used to indicate the sum of the absolute values of the difference values between the energy of the second channel signal and the energy of the downmix signal in the bin, and a target attenuation coefficient based on the difference value. The step of determining includes the step of determining the target damping coefficient based on the ratio between the first difference value and the second difference value.

  Alternatively, the target damping coefficient may be directly determined based on the first difference value and the second difference value.

  Related to the first aspect, in some implementations of the first aspect, prior to the step of determining a target damping coefficient based on the difference value, the method determines that the difference value is greater than a preset threshold. The method further includes the step of performing.

  The target only if the difference values between the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins are relatively large. The damping coefficient is determined and the initial reverberation gain parameter is adjusted based on the target damping coefficient. If the difference value is relatively small, the initial reverberation gain parameter may not be adjusted, which improves coding efficiency.

  If the difference value between the energy of the multi-channel signal and the energy of the downmix signal is less than a preset threshold, the initial reverberation gain parameter of the multi-channel signal is directly used as the target reverberation gain parameter of the multi-channel signal. May be determined.

  With respect to the first aspect, in some implementations of the first aspect, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

  The energy of the downmix signal can be calculated by using the energy of the first channel signal and the energy of the second channel signal, and the calculation process can be simplified without using the downmix signal itself.

  With respect to the first aspect, in some implementations of the first aspect, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponding to at least one subband of the plurality of channel signals. Also, any subband corresponds to only one attenuation coefficient.

  In addition, when the target damping coefficient includes a plurality of damping coefficients, the reverberation gain parameter can be adjusted more flexibly based on the target damping coefficient.

  With respect to the first aspect, in some implementations of the first aspect, each of the frequency bands in which the first channel signal and the second channel signal are located has a first frequency band and a second frequency band. Including the band, the attenuation coefficient corresponding to the subband in the first frequency band is less than or equal to the attenuation coefficient corresponding to the subband in the second frequency band, and the frequency of the first frequency band is the second It is smaller than the frequency of the frequency band.

  The reverberation gain parameters for the high and low frequency subbands can be adjusted to different degrees by setting different size attenuation factors for the reverberation gain parameters for the high and low frequency subbands. In addition, a better processing effect can be obtained during the reverberation processing.

  According to a second aspect, there is provided a multi-channel signal decoding method, the method comprising: a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, a first channel signal and a second channel signal. Determining the initial reverberation gain parameter of the channel signal, the first channel based on the correlation between the first channel signal and the downmix signal and the second channel signal and the downmix signal; The step of determining the identification information of the signal and the second channel signal, the identification information, the channel signal in the first channel signal and the second channel signal and its initial reverberation gain parameter needs to be adjusted And the first channel signal based on the step and downmix signals, the initial reverberation gain parameter, and the identification information used to indicate A second channel signal by quantizing, and a step of writing the second channel signal the first channel signal and the quantized quantized bit stream.

  Optionally, the correlation between the first channel signal or the second channel signal and the downmix signal is between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal. Or may be determined based on the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmix signal.

  In this application, the channel signal whose initial reverberation gain parameter needs to be adjusted can be determined based on the correlation between the channel signal and the downmix signal, so that the decoder side first After adjusting the initial reverberation gain parameters of some channel signals, reverberation processing can be performed on these channel signals, which can improve the quality of the channel signal obtained after the reverberation processing.

  In connection with the second aspect, in some implementations of the second aspect, the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal are Based on, the step of determining the identification information of the first channel signal and the second channel signal, the correlation between the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and Determining the identification information of the first channel signal and the second channel signal based on the correlation between the energy of the downmix signal.

  The correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal are conveniently measured by using the energy of the channel signal and the energy of the downmix signal. Can be done, so that the channel signal whose initial reverberation gain parameter needs to be adjusted can be conveniently determined.

  Related to the second aspect, in some implementations of the second aspect, the correlation between the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and the downmix signal. The step of determining the identification information of the first channel signal and the second channel signal based on the correlation with the energy of, the step of determining the first difference value and the second difference value, The difference value of 1 is the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the frequency bins, and the second difference value is the second value in the frequency bins. Is the sum of the absolute value of the difference value between the energy of the channel signal and the energy of the downmix signal, step, and the first channel signal based on the first difference value and the second difference value and And determining the identity of the second channel signal.

  It should be understood that the energy values of the first channel signal, the second channel signal, and the downmix signal may be the values obtained after the normalization process.

  The difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal require adjustment of its initial reverberation gain parameter. Between the energy of the first channel signal and the energy of the downmix signal in the frequency bins and between the energy of the second channel signal and the energy of the downmix signal in the frequency bins to determine a channel signal. Can be conveniently determined by comparing the difference values of Therefore, it is not necessary to compare the difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal in all frequency bands. .

  In connection with the second aspect, in some implementations of the second aspect, the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value. The step of determining is a step of determining the larger difference value in the first difference value and the second difference value as the target difference value, and a step of determining the identification information based on the target difference value, the identification information Is specifically used to indicate the channel signal corresponding to the target difference value, and the channel signal corresponding to the target difference value is the channel signal whose initial reverberation gain parameter needs to be adjusted. .

  Related to the second aspect, in some implementations of the second aspect, the method comprises determining a target damping coefficient based on the first difference value and the second difference value, the method comprising: The method further comprises the steps of: the coefficients are used to adjust the initial reverberation gain parameter of the target channel signal; and quantizing the target attenuation coefficient and writing the quantized target attenuation coefficient to a bitstream.

  The initial reverberation gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmix signal by using the attenuation coefficient.

  With respect to the second aspect, in some implementations of the second aspect, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponding to at least one subband of the target channel signal. Also, any subband corresponds to only one attenuation coefficient.

  In addition, when the target damping coefficient includes a plurality of damping coefficients, the reverberation gain parameter can be adjusted more flexibly based on the target damping coefficient.

  With respect to the second aspect, in some implementations of the second aspect, the target channel signal includes a first frequency band and a second frequency band and corresponds to subbands within the first frequency band. The attenuation coefficient is less than or equal to the attenuation coefficient corresponding to the subband in the second frequency band, and the frequency of the first frequency band is smaller than the frequency of the second frequency band.

  The reverberation gain parameters for the high and low frequency subbands can be adjusted to different degrees by setting different size attenuation factors for the reverberation gain parameters for the high and low frequency subbands. In addition, a better processing effect can be obtained during the reverberation processing.

  With respect to the second aspect, in some implementations of the second aspect, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

  The energy of the downmix signal is estimated or estimated by using the energy of multiple channel signals, which can reduce the calculation.

  According to a third aspect, there is provided a multi-channel signal decoding method, the method comprising: obtaining a bitstream; down-mixing a first channel signal and a second channel signal in the multi-channel signal; A step of determining the initial reverberation gain parameters of the first channel signal and the second channel signal and the identification information of the first channel signal and the second channel signal based on the bitstream, wherein the identification information is the first Of the first channel signal and the second channel signal based on the steps and identification information used to indicate the channel signal whose initial reverberation gain parameter needs to be adjusted. The channel signal of the second channel whose initial reverberation gain parameter needs to be adjusted is determined as the target channel signal. Comprising the steps of, and adjusting the initial reverberation gain parameter of the target channel signals.

  In this application, the identification information can be used to determine the channel signal whose initial reverberation gain parameter needs to be adjusted, and also the initial reverberation of the channel signal before reverberation processing is performed on the channel signal. The gain parameter is adjusted, which improves the quality of the channel signal obtained after reverberation processing.

  With respect to the third aspect, in some implementations of the third aspect, adjusting the initial reverberation gain parameter of the target channel signal includes determining a target attenuation coefficient and a target reverberation gain of the target channel signal. Adjusting the initial reverberation gain parameter of the target channel signal based on the target attenuation coefficient to obtain the parameter.

  The initial reverberation gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmix signal by using the attenuation coefficient.

  With respect to the third aspect, in some implementations of the third aspect, the step of determining a target damping coefficient comprises determining a preset damping coefficient as the target damping coefficient.

  By presetting the damping coefficient, the process of determining the target damping coefficient can be simplified, thereby improving the decoding efficiency.

  With respect to the third aspect, in some implementations of the third aspect, the step of determining the target damping coefficient comprises obtaining the target damping coefficient based on the bitstream.

  If the bitstream includes a target attenuation coefficient, the target attenuation coefficient may be obtained directly from the bitstream, and the process of determining the target attenuation coefficient can also be simplified, thereby decoding Efficiency is improved.

  With respect to the third aspect, in some implementations of the third aspect, the step of determining a target attenuation coefficient comprises bit-counting the inter-channel level difference between the first channel signal and the second channel signal. Obtaining from the stream, determining a target attenuation coefficient based on the inter-channel level difference, or determining a target attenuation coefficient based on the inter-channel level difference and the downmix signal.

  The target attenuation coefficient can be more flexibly and accurately determined based on the inter-channel level difference, the downmix signal, etc. so that the initial reverberation parameter of the channel signal can be adjusted more accurately based on the attenuation coefficient.

  With respect to the third aspect, in some implementations of the third aspect, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponding to at least one subband of the target channel signal. Also, any subband corresponds to only one attenuation coefficient.

  In addition, when the target damping coefficient includes a plurality of damping coefficients, the reverberation gain parameter can be adjusted more flexibly based on the target damping coefficient.

  With respect to the third aspect, in some implementations of the third aspect, the target channel signal includes a first frequency band and a second frequency band and corresponds to subbands within the first frequency band. The attenuation coefficient is less than or equal to the attenuation coefficient corresponding to the subband in the second frequency band, and the frequency of the first frequency band is smaller than the frequency of the second frequency band.

  The reverberation gain parameters for the high and low frequency subbands can be adjusted to different degrees by setting different size attenuation factors for the reverberation gain parameters for the high and low frequency subbands. In addition, a better processing effect can be obtained during the reverberation processing.

  According to a fourth aspect, an encoder is provided, the encoder comprising a module or unit configured to perform the method in the first aspect or various implementations of the first aspect.

  According to a fifth aspect, an encoder is provided, the encoder comprising a module or unit configured to perform the method in the second aspect or various implementations of the second aspect.

  According to a sixth aspect, a decoder is provided and an encoder comprises a module or unit configured to perform the method in the third aspect or various implementations of the third aspect.

  According to a seventh aspect, an encoder is provided. The encoder includes a memory and a processor, the memory is configured to store the program, the processor is configured to execute the program, and when the program is executed, the processor is the first aspect or the first aspect. Perform methods in various implementations.

  According to an eighth aspect, an encoder is provided. The encoder includes a memory and a processor, the memory is configured to store the program, the processor is configured to execute the program, and when the program is executed, the processor is of the second aspect or the second aspect. Perform methods in various implementations.

  According to a ninth aspect, a decoder is provided. The decoder includes a memory and a processor, the memory is configured to store the program, the processor is configured to execute the program, and when the program is executed, the processor is the third aspect or the third aspect. Perform methods in various implementations.

  According to a tenth aspect, there is provided a computer-readable medium, the computer-readable medium storing program code to be executed by a device, the program code being in the first aspect or various aspects of the first aspect. Includes instructions used to carry out the methods in the implementation.

  According to an eleventh aspect, there is provided a computer readable medium, the computer readable medium storing program code to be executed by a device, the program code also comprising the second aspect or various aspects of the second aspect. Includes instructions used to carry out the methods in the implementation.

  According to a twelfth aspect, a computer-readable medium is provided, the computer-readable medium stores program code to be executed by a device, the program code also including the third aspect or various aspects of the third aspect. Includes instructions used to carry out the methods in the implementation.

3 is a schematic flowchart for encoding a left channel signal and a right channel signal in the related art. 3 is a schematic flowchart for decoding a left channel signal and a right channel signal in the related art. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the decoder concerning one Embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the decoder concerning one Embodiment of this application.

  Hereinafter, the technical solution of the present application will be described with reference to the accompanying drawings. In order to better understand the multi-channel signal coding method and the multi-channel signal decoding method in the embodiments of this application, in the following, first, referring to FIG. 1 and FIG. The method and the multi-channel signal decoding method will be briefly described.

  FIG. 1 shows a process of encoding a left channel signal and a right channel signal in the prior art. The encoding process shown in FIG. 1 specifically includes the following steps.

  110. Spatial parameter analysis and downmix processing is performed on the left channel signal (represented by L in the figure) and the right channel signal (represented by R in the figure).

  Specifically, step 110 specifically performs spatial parameter analysis on the left channel signal and the right channel signal to obtain the spatial parameter of the left channel signal and the spatial parameter of the right channel signal, and Performing downmix processing on the channel signal and the right channel signal to obtain a downmix signal (the downmix signal obtained after the downmix processing is a monaural audio signal, and the first two channels of the audio signal are It is converted to one channel of the audio signal by the mixing process).

  Spatial parameters (sometimes referred to as spatial sensing parameters) are inter-channel correlation (IC), inter-channel level difference (ILD), inter-channel time difference (Inter-channel Time). Difference, ITD), inter-channel phase difference (IPD), and the like.

  IC stands for cross-correlation or coherence between channels. This parameter determines the detection of the sound field range and can improve the spatial perception and sound stability of the audio signal. ILD is used to distinguish the horizontal angle of a stereo source and represents the intensity difference between channels, and this parameter also affects the frequency content of the whole spectrum. ITD and IPD are spatial parameters that represent the horizontal direction of the sound source. ITD and IPD represent channel time and phase difference. The parameters mainly affect the frequency components below 2 kHz. For a two-channel signal, ITD may represent the time delay between the stereo left and right channel signals, and IPD is the time-adjusted stereo left and right channel waveforms. It may represent similarity. The ILD, ITD, and IPD can determine the detection of the human ear at the position of the sound source, effectively determine the sound field position, and play an important role in stereo signal restoration.

  120. The downmix signal is encoded to obtain a bitstream.

  130. Encode the spatial parameters to get the bitstream.

  140. A bitstream obtained by encoding a downmix signal and a bitstream obtained by encoding a spatial parameter are multiplexed to obtain one bitstream.

  The bitstream obtained by the encoding is stored or transmitted to the decoder side device.

  FIG. 2 shows a process of decoding a left channel signal and a right channel signal in the prior art. The decoding process shown in FIG. 2 specifically includes the following steps.

  210. The bitstream is demultiplexed to separately obtain the bitstream obtained by encoding the downmix signal and the bitstream obtained by encoding the spatial parameter.

  220. The bitstream is decoded to obtain a downmix signal of the left channel signal and the right channel signal, a spatial parameter of the left channel signal, and a spatial parameter of the right channel signal.

  The spatial parameters include ICs for left and right channel signals.

  230. An uncorrelated signal is acquired based on the downmix signal and the spatial parameter of the previous frame.

  The left channel signal and the right channel signal are obtained based on the decoded downmix signal and the uncorrelated signal of the current frame.

  240. Based on the spatial parameters, the left channel signal, and the right channel signal, the finally output left channel signal and right channel signal (represented by L ′ and R ′ in FIG. 2) are obtained.

  The left channel signal and the right channel signal in step 240 (represented by L ′ and R ′ in FIG. 2, respectively) are obtained by decoding and compared with the left channel signal and the right channel signal which are encoded at the encoder side. It should be understood that it may be distorted to some extent.

  Specifically, the downmix signal may be filtered and then the inter-channel correlation parameter is used to correct the filtered downmix signal to obtain an uncorrelated signal.

  The purpose of generating the uncorrelated signal is to improve the reverberation feeling of the stereo signal finally generated on the decoder side and to widen the sound field width of the stereo signal, so that the output audio signal is related to the auditory sense. More mellow is enough. The sensation of reverberation is essentially delayed by, for example, reflecting and refracting the original audio signal differently, and then superimposing the reflected and refracted audio signal on the original audio signal so that it enters the human ear. That is the effect.

  In the prior art, after the IC is obtained, the correlation of different channel signals is not considered in order to adjust the IC adaptively. In this case, if reverberation processing is performed on the channel signal based on the previously obtained IC, a relatively bad auditory effect may be caused. For example, if the correlation between different channel signals is relatively low, the previously obtained IC is still used to correct the decorrelated signal, and then the decorrelation is performed to perform the same reverberation on different channel signals. If the signal is used, the quality of the channel signal finally output from the decoder side is relatively low. That is, since the difference between different channel signals is relatively large, the reverberation effect of the channel signals will be reduced if reverberation is performed on the different channel signals by still using the uncorrelated signal corrected by the previous relatively large IC. Although not increased, the output channel signal may be distorted.

  Therefore, the embodiments of this application provide a method for encoding or decoding a multi-channel signal. In this way, the reverberation gain parameter can be correspondingly adjusted based on the correlation between different channel signals, and the decorrelated signal is corrected by using the adjusted reverberation gain parameter. Reverberation is then performed on the different channel signals by using the uncorrelated signals. Thus, when reverberation processing is performed on different channel signals, the correlation between different channel signals is taken into account, which results in better quality of the output channel signals.

  FIG. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. The method of FIG. 3 may be performed by an encoder side device or encoder. The method of FIG. 3 includes the following steps.

  310. A downmix signal of the first channel signal and the second channel signal in the multi-channel signal, and an initial reverberation gain parameter of the first channel signal and the second channel signal are determined.

  In this embodiment of this application, the sequence for determining the downmix signal and determining the initial reverberation gain parameter is not limited, and the downmix signal and the initial reverberation gain parameter may be determined simultaneously or sequentially. Should be understood.

  The initial reverberation gain parameter may be a reverberation gain parameter obtained after the spatial parameter analysis is performed on the first channel signal and the second channel signal.

  Specifically, the downmix signal may be obtained by performing downmix processing on a plurality of channel signals. The spatial parameter of the first channel signal and the spatial parameter of the second channel signal are obtained by performing a spatial parameter analysis on the first channel signal and the second channel signal, the spatial parameter being the first channel signal. Includes initial reverberation gain parameters for the signal and the second channel signal.

  The first channel signal and the second channel signal may correspond to the same spatial parameter, and correspondingly, the first channel signal and the second channel signal correspond to the same initial reverberation gain parameter. It should be understood that it is good. That is, the spatial parameter of the first channel signal and the spatial parameter of the second channel signal may be the same, and the initial reverberation gain parameter of the first channel signal and the second channel signal are the same. Good.

  Further, assuming that each of the first channel signal and the second channel signal includes 10 subbands, and each subband corresponds to one reverberation gain parameter, the first channel signal and the second channel signal The reverberation gain parameters corresponding to subbands of the signal having the same index value may be the same.

  Further, the first channel signal, the second channel signal, and the downmix signal may be channel signals obtained after the normalization processing.

  320. Based on the correlation between the first channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter, the first channel signal and the second channel signal The target reverberation gain parameter of is determined.

  Optionally, the correlation between the first channel signal or the second channel signal and the downmix signal is between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal. Or may be determined based on the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmix signal.

  Specifically, when the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmix signal is relatively small, there is a correlation between the first channel signal and the downmix signal. It may be considered relatively large. If the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmix signal is relatively large, the correlation between the first channel signal and the downmix signal is considered to be relatively small. May be done.

  The difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal is specifically the energy of the first channel signal or the energy of the second channel signal It may be a difference value with the energy of the mix signal. Similarly, the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmix signal is, in particular, the amplitude of the first channel signal or the second channel signal. It may be a difference value between the amplitude and the amplitude of the downmix signal.

  Further, the correlation between the first channel signal or the second channel signal and the downmix signal, instead, the phase of the first channel signal or the second channel signal, the period etc. and the phase of the downmix signal, You may also point out the difference with a period etc.

  330. Quantize the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter, and bitstream the quantized first channel signal and the quantized second channel signal Write in.

  When the multi-channel signal has more than two channel signals, for example when the multi-channel signal comprises a first channel signal, a second channel signal, a third channel signal, and a fourth channel signal, the first The second channel signal and the second channel signal are processed by using the method of FIG. 3, and the third channel signal and the fourth channel signal are processed by using the method of FIG. Should be understood.

  In this application, the correlation between the channel signal and the downmix signal is considered when the target reverberation gain parameter of the channel signal is determined. In this way, a better processing effect can be obtained when the reverberation processing is performed on the channel signal based on the target reverberation gain parameter, which improves the quality of the channel signal obtained after the reverberation processing.

  Optionally, in one embodiment, a first channel signal based on the correlation between the first channel signal and the downmix signal, a correlation between the second channel signal and the downmix signal, and an initial reverberation gain parameter. The step of determining the target reverberation gain parameter of the channel signal and the second channel signal is based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal. Determining a target attenuation coefficient, and adjusting the initial reverberation gain parameter based on the target attenuation coefficient to obtain the target reverberation gain parameter.

  Specifically, the step of determining the target attenuation coefficient based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal includes It may be a step of calculating the target attenuation coefficient based on the correlation with the mix signal, or alternatively, the preset attenuation coefficient may be used as the target attenuation coefficient after the correlation between the channel signal and the downmix signal is considered. It may be a step of directly determining.

  The initial reverberation gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmix signal by using the attenuation coefficient.

  For example, when the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal are relatively large (in this case, the first channel signal is the second channel signal). (Which may be considered to be relatively similar to the channel signal of), a target attenuation coefficient with a relatively small value may be determined. However, when the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal are relatively small (in this case, the first channel signal is the second channel signal). (Which may be considered to be relatively different from the channel signal of), a target attenuation coefficient with a relatively large value may be determined.

  In some embodiments, the correlation between the plurality of channel signals and the downmix signal is the difference between the energy of the plurality of channel signals and the energy of the downmix signal, or the amplitude and the downmix of the plurality of channel signals. It may also refer to the difference between the amplitudes of the mix signals. The difference between the energy of the plurality of channel signals and the energy of the downmix signal may be specifically a difference value between the energy of the plurality of channel signals and the energy of the downmix signal. Similarly, the difference between the amplitudes of the plurality of channel signals and the downmix signal may be specifically a difference value between the amplitudes of the plurality of channel signals and the downmix signal. . Additionally, the correlation between the plurality of channel signals and the downmix signal may instead refer to the difference between the phase, period, etc. of the plurality of channel signals and the phase, period, etc. of the downmix signal.

  In some embodiments, the correlation between the first channel signal or the second channel signal and the downmix signal is the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal. And a target damping coefficient is determined.

  The correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal are conveniently measured by using the energy of the channel signal and the energy of the downmix signal. The target attenuation coefficient can be conveniently determined by comparing the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal.

  Optionally, in one embodiment, both the first channel signal and the second channel signal include a plurality of frequency bins, and the correlation between the first channel signal and the downmix signal and the second channel signal. Determining the target attenuation coefficient based on the correlation between the channel signal and the downmix signal includes between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and in the plurality of frequency bins. The method includes determining a difference value between the energy of the second channel signal and the energy of the downmix signal, and determining a target attenuation coefficient based on the difference value.

  The difference value between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins is the difference between the energy of the first channel signal and the energy of the downmix signal in the plurality of same frequency bins. It may be a value. For example, the first channel signal includes three frequency bins (first frequency channel number, second frequency channel number, and third frequency channel number). In this case, the difference value between the energy of the first channel signal and the energy of the downmix signal in the three frequency bins, specifically, the first channel signal and the downmix signal in the first frequency channel number. And a difference value between the first frequency signal and the downmix signal in the second frequency channel number, and between the first channel signal and the downmix signal in the third frequency channel number Is the difference value of.

  Similarly, the difference value between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins is the difference between the energy of the second channel signal and the energy of the downmix signal in the plurality of same frequency bins. It may be a difference value between them.

  Optionally, the difference value between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins is between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins. It may be the sum of the absolute values of the difference values between them. Similarly, the difference value between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins is between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. It may be the sum of the absolute values of the difference values of.

  It should be understood that the energy values of the first channel signal, the second channel signal, and the downmix signal may be the values obtained after the normalization process.

  The difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal is the difference of the first channel signal in the plurality of frequency bins. It can be conveniently determined by comparing the difference value between the energy and the energy of the downmix signal and the difference value between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. Yes, and the damping factor is further determined. Therefore, it is not necessary to compare the difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal in all frequency bands. .

  Optionally, in one embodiment, between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. Is a step of determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, the first difference value is a plurality of frequencies. Steps used to indicate the sum of the absolute values of the differences between the energy of the first channel signal and the energy of the downmix signal in the bin, and the energy of the second channel signal and the energy of the downmix signal Determining a second difference value between the second difference value and the first channel in the plurality of frequency bins. Based on the step and the first difference value and the second difference value, used to indicate the sum of the absolute values of the difference values between the signal energy and the downmix signal energy. And determining.

  The step of determining the target damping coefficient based on the first difference value and the second difference value, the step of determining the target damping coefficient based on the ratio between the first difference value and the second difference value. May be included.

ここで、diff＿l＿hは第1の差分値であり、diff＿r＿hは第2の差分値であり、左チャネル信号及び右チャネル信号のそれぞれの周波数帯域が高周波部分及び低周波部分を含み、M1が高周波部分の開始周波数チャネル番号であり、M2が高周波部分の終了周波数チャネル番号であり、mag＿l［k］は、M1とM2との間の周波数チャネル番号における左チャネル信号のエネルギー又は振幅値であり、mag＿r［k］は、M1とM2の間のインデックスkを伴う周波数チャネル番号における右チャネル信号のエネルギー又は振幅値であり、mag＿dmx［k］は、M1とM2の間のインデックスkを伴う周波数チャネル番号におけるダウンミックス信号のエネルギー又は振幅値であり、また、mag＿dmx［k］は、ダウンミックス信号自体を使用することによって計算により得られてもよく、又は、左チャネル信号及び右チャネル信号のエネルギー又は振幅値に基づいて計算により得られてもよい。 Specifically, when the first channel signal is the left channel signal and the second channel signal is the right channel signal, the first difference value and the second difference value are calculated according to the following equations. obtain.

Here, diff_l_h is the first difference value, diff_r_h is the second difference value, the frequency bands of the left channel signal and the right channel signal include high-frequency parts and low-frequency parts, and M1 is the high-frequency part. Is the starting frequency channel number, M2 is the ending frequency channel number of the high frequency part, mag_l [k] is the energy or amplitude value of the left channel signal at the frequency channel number between M1 and M2, mag_r [k ] Is the energy or amplitude value of the right channel signal at the frequency channel number with index k between M1 and M2, and mag_dmx [k] is the downmix at the frequency channel number with index k between M1 and M2. Is the energy or amplitude value of the signal, and mag_dmx [k] may be calculated by using the downmix signal itself, or It may be obtained by calculation based on the energy or amplitude of the left channel signal and right channel signal.

  When the target damping coefficient is determined based on the first difference value and the second difference value, the ratio between the first difference value and the second difference value is directly determined as the target damping coefficient. May be. For example, the first difference value is a and the second difference value is b. If a <b, a / b is determined as the target damping coefficient, or if a> b, b / a is determined as the target damping coefficient. Further, after the target attenuation coefficient is determined based on the first difference value and the second difference value, some smoothing process may be performed on the target attenuation coefficient and the attenuation coefficient of the previous frame, and, The target attenuation coefficient obtained after the smoothing process is used to further adjust the initial reverberation gain parameter of the multiple channel signals.

  Optionally, in one embodiment, before the target damping coefficient is determined based on the aforementioned difference value, the method of FIG. 3 further comprises determining that the difference value is greater than a preset threshold.

  Here, the difference value is larger than a preset threshold value herein, between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and the energy of the second channel signal. It may mean that the difference value between the energy of the downmix signal is greater than the same preset threshold, or the difference between the energy of the first channel signal and the energy of the downmix signal is preset. Greater than the preset first threshold and may mean that the difference between the energy of the second channel signal and the energy of the downmix signal is greater than the preset second threshold. Should be understood.

  The target only if the difference values between the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins are relatively large. The damping coefficient is determined and the initial reverberation gain parameter is adjusted based on the target damping coefficient. If the difference value is relatively small, the initial reverberation gain parameter may not be adjusted, which improves coding efficiency.

  For example, when the difference value between the energy of the first channel signal and the energy of the downmix signal is larger than M (M is 0.5 to 1) times the energy of the first channel signal, The difference value between the energies of the channels and the energy of the downmix signal may be considered to be greater than a preset threshold. In this case, the preset threshold is M times the energy of the first channel signal. Alternatively, when the ratio of the difference value between the energy of the first channel signal and the energy of the downmix signal to the energy of the first channel signal is larger than M, the energy of the first channel and the downmix signal May be considered to be greater than a preset threshold.

  If the difference value between the energy of the multi-channel signal and the energy of the downmix signal is less than a preset threshold, the initial reverberation gain parameter of the multi-channel signal is directly used as the target reverberation gain parameter of the multi-channel signal. May be determined.

  Optionally, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

  The energy of the downmix signal can be calculated by using the energy of the first channel signal and the energy of the second channel signal, and the calculation process can be simplified without using the downmix signal itself.

  Indeed, in this embodiment of this application, the energy of the downmix signal may instead be calculated directly based on the downmix signal itself.

  Optionally, in one embodiment, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the plurality of channel signals, and any subband is a single It corresponds only to the damping coefficient.

  For example, the indices of subbands included in each of the first channel signal and the second channel signal are 0 to 9. The first channel signal and the second channel signal each include 10 reverberation gain parameters, each subband corresponds to one reverberation gain parameter, the target attenuation coefficient includes 5 attenuation coefficients, and each The damping coefficient corresponds to two subbands, or the target damping coefficient includes ten damping coefficients and each damping coefficient corresponds to one subband.

  In addition, when the target damping coefficient includes a plurality of damping coefficients, the reverberation gain parameter can be adjusted more flexibly based on the target damping coefficient. For example, the reverberation gain parameters corresponding to subbands of channel signals whose index is 0 to 4 need to be adjusted slightly, but correspond to subbands whose index of channel signals are 5 to 9. The reverberation gain parameter to be adjusted needs to be adjusted significantly. In this case, a relatively small attenuation coefficient may be set for the reverberation gain parameter corresponding to the subband whose index is 0 to 4, and the reverberation gain corresponding to the subband whose index is 5 to 9 may be set. A relatively large damping coefficient is set for the parameters.

  Optionally, in one embodiment, each of the first channel signal and the second channel signal (the frequency band occupied by the first channel signal and the frequency band occupied by the second channel signal are the same) Including a first frequency band and a second frequency band, the attenuation coefficient corresponding to the subband in the first frequency band is less than or equal to the attenuation coefficient corresponding to the subband in the second frequency band, and The frequency of the 1st frequency band is smaller than the frequency of the 2nd frequency band.

  For example, each of the frequency bands in which the first channel signal and the second channel signal are located includes a low frequency portion and a high frequency portion, and the target attenuation coefficient includes a plurality of attenuation coefficients. The low frequency portion corresponds to at least one damping coefficient, the high frequency portion corresponds to at least one damping coefficient, and the damping coefficient corresponding to the low frequency portion is smaller than the damping coefficient corresponding to the high frequency portion.

  The reverberation gain parameters for the high and low frequency subbands can be adjusted to different degrees by setting different size attenuation factors for the reverberation gain parameters for the high and low frequency subbands. In addition, a better processing effect can be obtained during the reverberation processing.

  FIG. 4 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. In FIG. 4, the channel signal includes a left channel signal and a right channel signal, and the process of encoding the left channel signal and the right channel signal specifically includes the following steps.

  410. Compute the spatial parameters of the left channel signal and the right channel signal.

  The spatial parameters include initial reverberation gain parameters for the left and right channel signals, and other spatial parameters.

  420. Downmix processing is performed on the left channel signal (denoted by L in the figure) and the right channel signal (denoted by R in the figure) to obtain the downmix signal.

  430. Determine difference values between the energy of the left channel signal and the energy of the downmix signal and between the energy of the right channel signal and the energy of the downmix signal.

  Specifically, each of the left channel signal and the right channel signal may be divided into a high frequency portion and a low frequency portion, and between the energy of the left channel signal and the energy of the downmix signal in the high frequency portion and the right portion. The difference value between the energy of the channel signal and the energy of the downmix signal is the difference value between the energy of the left channel signal and the energy of the downmix signal and between the energy of the right channel signal and the energy of the downmix signal. Is determined as

  440. The reverberation gain parameters of the left channel signal and the right channel signal are adjusted based on the difference values between the energy of the left channel signal and the energy of the downmix signal and between the energy of the right channel signal and the energy of the downmix signal.

  Specifically, the encoder side determines the target attenuation coefficient based on the difference values between the energy of the left channel signal and the energy of the downmix signal and between the energy of the right channel signal and the energy of the downmix signal. In addition, the reverberation gain parameters of the left channel signal and the right channel signal may be adjusted based on the target attenuation coefficient.

  450. Quantize the downmix signal, the adjusted reverberation gain parameter, and other spatial parameters to obtain a bitstream.

  FIG. 5 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of this application. In FIG. 5, the channel signal includes a left channel signal and a right channel signal. In FIG. 5, the bitstream generated by the encoding in the encoding method of FIG. 4 may be decoded. Specifically, the decoding process of FIG. 5 includes the following steps.

  510. Obtain a bitstream of left and right channel signals.

  520. Decode the bitstream to obtain the downmix signal.

  530. The bitstream is decoded to obtain the spatial parameters of the left and right channel signals.

  The spatial parameter includes a reverberation gain parameter adjusted by the encoder side, that is, the encoder side encodes the adjusted reverberation gain parameter. In this way, after decoding the bitstream, the decoder side acquires the reverberation gain parameter adjusted by the encoder side.

  Step 520 and step 530 may not be executed in sequence but may be executed simultaneously.

  540. Subsequent processing (eg smoothing filtering) is performed on the spatial parameters obtained by the decoding.

  550. An uncorrelated signal is acquired based on the downmix signal and the reverberation gain parameter obtained by decoding (the reverberation gain parameter is the reverberation gain parameter adjusted by the encoder side).

  An upmix process is performed based on the spatial parameter and the downmix signal processed in step 540 to obtain a left channel signal and a right channel signal.

  570. Reverberation processing is separately performed on the left channel signal and the right channel signal based on the uncorrelated signal.

  In the method shown in FIG. 5, the reverberation gain parameter on which the reverberation processing performed on the left channel signal and the right channel signal is based is between the left channel signal and the downmix signal and between the right channel signal and the downmix signal. It has been adjusted based on the correlation. In this way, a corresponding reverberation process can be performed on the basis of the difference between the left channel signal and the right channel signal, which improves the quality of the channel signal obtained after the reverberation process.

  In the encoding method of FIG. 3, the encoder side determines whether the initial reverberation gain parameter of the channel signal needs to be adjusted. When it is necessary to adjust the initial reverberation gain parameter of the channel signal, the encoder side adjusts the initial reverberation gain parameter of the channel signal to encode the adjusted reverberation gain parameter, and thereby obtain by decoding. The decoder side directly performs reverberation processing based on the reverberation gain parameter.

  In practice, the encoder side may instead only decide whether the initial reverberation gain parameter of the channel signal needs to be adjusted. When it is necessary to adjust the initial reverberation gain parameter of the channel signal, the encoder side sends corresponding instruction information to the encoder side. After receiving the indication information, the decoder side adjusts the initial reverberation gain parameter of the channel signal.

  FIG. 6 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. The method of FIG. 6 includes the following steps.

  610. A downmix signal of the first channel signal and the second channel signal in the multi-channel signal, and an initial reverberation gain parameter of the first channel signal and the second channel signal are determined.

  Specifically, the downmix signal may be obtained by performing a downmix process on the first channel signal and the second channel signal, and the spatial parameter is the first channel signal and the second channel signal. Obtained by performing a spatial parameter analysis on the channel signals of, wherein the spatial parameters include initial reverberation gain parameters of the first channel signal and the second channel signal.

  It should be appreciated that the downmix signal and the initial reverberation gain parameter may be determined simultaneously or sequentially.

  The first channel signal and the second channel signal may correspond to the same spatial parameter, and in particular, the first channel signal and the second channel signal also correspond to the same initial reverberation gain parameter. It should be understood. That is, the spatial parameters of the first channel signal and the second channel signal are the same, and the initial reverberation gain parameters of the first channel signal and the second channel signal are the same.

  Further, assuming that each of the first channel signal and the second channel signal includes 10 subbands, and each subband corresponds to one reverberation gain parameter, the first channel signal and the second channel signal The reverberation gain parameters corresponding to subbands of the signal having the same index value may be the same.

  620. Determining the identification information of the first channel signal and the second channel signal based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, The identification information is used to indicate which channel signal is in the first channel signal and the second channel signal and whose initial reverberation gain parameter needs to be adjusted.

  Optionally, the correlation between the first channel signal or the second channel signal and the downmix signal is between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal. Or may be determined based on the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmix signal.

  Specifically, when the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmix signal is relatively small, there is a correlation between the first channel signal and the downmix signal. It may be considered relatively large. If the difference between the energy or amplitude of the first channel signal and the energy or amplitude of the downmix signal is relatively large, the correlation between the first channel signal and the downmix signal is considered to be relatively small. May be done.

  The difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal is specifically the energy of the first channel signal or the energy of the second channel signal It may be a difference value with the energy of the mix signal. Similarly, the difference between the amplitude of the first channel signal or the amplitude of the second channel signal and the amplitude of the downmix signal is, in particular, the amplitude of the first channel signal or the second channel signal. It may be a difference value between the amplitude and the amplitude of the downmix signal.

  Further, the correlation between the first channel signal or the second channel signal and the downmix signal, instead, the phase of the first channel signal or the second channel signal, the period etc. and the phase of the downmix signal, You may also point out the difference with a period etc.

  The first channel signal, the second channel signal, and the downmix signal may be channel signals obtained after the normalization process.

  Specifically, the identification information may indicate that the first channel signal or the second channel signal is a channel signal whose initial reverberation gain parameter needs to be adjusted, or the first channel signal And the second channel signal is a channel signal whose reverberation gain parameter needs to be adjusted, or adjusts the reverberation gain parameter for both the first channel signal and the second channel signal. It may indicate that it is not necessary.

  In some embodiments, the identification information may indicate a channel signal in the plurality of channel signals whose initial reverberation gain parameter needs to be adjusted by using the value of the identifier field. For example, the identifier field of the identification information occupies 2 bits. A value of 00 in the identifier field indicates that neither the initial reverberation gain parameter of the first channel signal nor the initial reverberation gain parameter of the second channel signal needs to be adjusted. A value of 01 in the identifier field indicates that only the initial reverberation gain parameter of the first channel signal needs to be adjusted. A value of 10 in the identifier field indicates that only the initial reverberation gain parameter of the second channel signal needs to be adjusted. A value of 11 in the identifier field indicates that both the initial reverberation gain parameter of the first channel signal and the second channel signal need to be adjusted.

  In some embodiments, the first channel signal and the second channel based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal. The step of determining the identification information of the signal is based on a correlation between the energy of the first channel signal and the energy of the downmix signal and the first channel signal based on the correlation between the energy of the second channel signal and the energy of the downmix signal. Determining the identification information of the second channel signal and the second channel signal.

  The correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal are conveniently measured by using the energy of the channel signal and the energy of the downmix signal. Can be done, so that the channel signal whose initial reverberation gain parameter needs to be adjusted can be conveniently determined.

  In some embodiments, the energy or amplitude of the downmix signal may be calculated based on the energy of the first channel signal and the energy of the second channel signal, thereby simplifying the calculation process. . Alternatively, the energy of the downmix signal may be calculated directly based on the downmix signal itself.

  630. Downmix signal, the initial reverberation gain parameter, and quantized the first channel signal and the second channel signal based on the identification information, the quantized first channel signal and the quantized second channel signal and To the bitstream.

  In this application, by determining the relationship between the preset threshold and the magnitude of the difference value between the energy of the channel signal and the energy of the downmix signal, the energy of the channel signal is significantly different from the energy of the downmix signal. In addition, the channel signal can be determined as the channel signal whose reverberation gain parameter needs to be adjusted. Therefore, the decoder side can first adjust the initial reverberation gain parameter of the channel signal and then perform reverberation processing on the channel signal, thereby improving the quality of the channel signal obtained after the reverberation processing. You can

  Optionally, in an embodiment, the first channel signal is based on a correlation between the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and the energy of the downmix signal. The step of determining the identification information of the channel signal and the second channel signal is a step of determining the first difference value and the second difference value, the first difference value is the first in the plurality of frequency bins. The sum of the absolute values of the difference values between the energy of the channel signal and the energy of the downmix signal, the second difference value between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. Is the sum of the absolute value of the difference value between, step, based on the first difference value and the second difference value, the identification information of the first channel signal and the second channel signal. And a step of constant.

  The difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal require adjustment of its initial reverberation gain parameter. Between the energy of the first channel signal and the energy of the downmix signal in the frequency bins and between the energy of the second channel signal and the energy of the downmix signal in the frequency bins to determine a channel signal. Can be conveniently determined by comparing the difference values of Therefore, it is not necessary to compare the difference between the energy of the first channel signal and the energy of the downmix signal and the difference between the energy of the second channel signal and the energy of the downmix signal in all frequency bands. .

  Optionally, the step of determining the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value, the first difference value and the second difference value. In the step of determining the larger difference value as the target difference value and the step of determining the identification information based on the target difference value, the identification information specifically indicating the target channel signal corresponding to the target difference value. And the channel signal corresponding to the target difference value is the channel signal whose initial reverberation gain parameter needs to be adjusted.

  Specifically, the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the multiple frequency bins is downmixed with the energy of the second channel signal in the multiple frequency bins. The first channel signal may be determined as the channel signal whose initial reverberation gain parameter needs to be adjusted if it is greater than the sum of the absolute values of the difference values with the energy of the signal.

  Furthermore, the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the frequency bins and the energy of the second channel signal and the energy of the downmix signal in the frequency bins If the sum of the absolute values of the difference values between and is both relatively large (eg, both are greater than a preset threshold), then another piece of identification information may be determined, and the identification information Indicates that both the initial reverberation gain parameters of the first channel signal and the second channel signal need to be adjusted.

  Specifically, in some embodiments, the sum of the absolute values of the difference values between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins is added. The step of determining the identification information of the first channel signal and the second channel signal based on the absolute value of the difference value between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins Generating the first identity when the sum is greater than a preset threshold, the first identity being to indicate that the initial reverberation gain parameter of the first channel signal needs to be adjusted. The absolute value of the step used and the difference between the energy of the second channel signal and the energy of the downmix signal in the multiple frequency bins. A second identification information when the sum of the two is greater than a preset threshold, the second identification information to indicate that the initial reverberation gain parameter of the second channel signal needs to be adjusted. Are used, including steps.

  By determining the relationship between the preset threshold and the magnitude of the difference value between the energy of the channel signal and the energy of the downmix signal, the reverberation of the channel signal when it differs significantly from the energy of the downmix signal. The channel signal can be determined as the channel signal for which the gain parameter needs to be adjusted. Therefore, the decoder side can first adjust the initial reverberation gain parameter of the channel signal and then perform reverberation processing on the channel signal, thereby improving the quality of the channel signal obtained after the reverberation processing. You can

  It should be understood that the identification information of the first channel signal and the second channel signal may be one piece of identification information or two pieces of identification information. For example, when it is necessary to adjust both the initial reverberation gain parameter of the first channel signal and the second channel signal, the identification information of the first channel signal and the second channel signal is one fragment of the identification information. And the identification information indicates that both the initial reverberation gain parameters of the first channel signal and the second channel signal need to be adjusted. Alternatively, the identification information of the first channel signal and the second channel signal, two fragments of the identification information, that is, each of the first identification information and the second identification information, the first identification information, It is used to indicate that the initial reverberation gain parameter of the first channel signal needs to be adjusted, and the second identification information also requires that the initial reverberation gain parameter of the second channel signal needs to be adjusted. Used to indicate If the channel signal has no corresponding identification information, it indicates that the initial reverberation gain parameter of the channel signal does not need to be adjusted. That is, when the identification information includes only the first identification information, it is necessary to adjust the initial reverberation gain parameter of only the first channel signal in the first channel signal and the second channel signal.

  Optionally, in some embodiments, if the initial reverberation gain parameter of the first channel signal needs to be adjusted, the method of FIG. 6 is based on the first difference value and the second difference value. A step of determining a target attenuation coefficient, wherein the target attenuation coefficient is used to adjust an initial reverberation gain parameter of the target channel signal, the step of quantizing the target attenuation coefficient, and the quantized target attenuation coefficient To the bitstream.

  The initial reverberation gain parameter of the channel signal can be flexibly adjusted based on the correlation value between the channel signal and the downmix signal by using the attenuation coefficient.

  It should be understood that the first difference value and the second difference value may be calculated by referring to equations (1) and (2) above.

  When the target damping coefficient is determined based on the first difference value and the second difference value, the target damping coefficient is determined based on the ratio between the first difference value and the second difference value. May be.

  In some embodiments, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the target channel signal, and any subband has only one attenuation coefficient. Corresponding to. For example, a multi-channel signal may include multiple subbands and adjacent subbands may correspond to one attenuation coefficient.

  In addition, when the target damping coefficient includes a plurality of damping coefficients, the reverberation gain parameter can be adjusted more flexibly based on the target damping coefficient.

  In some other embodiments, the target channel signal comprises a first frequency band and a second frequency band, and the attenuation factors corresponding to subbands within the first frequency band are within the second frequency band. It is less than or equal to the attenuation coefficient corresponding to the subband, and the frequency of the first frequency band is smaller than the frequency of the second frequency band.

  The reverberation gain parameters for the high and low frequency subbands can be adjusted to different degrees by setting different size attenuation factors for the reverberation gain parameters for the high and low frequency subbands. In addition, a better processing effect can be obtained during the reverberation processing.

  For example, the frequency band in which the target channel signal is located includes a low frequency part and a high frequency part, and the target attenuation coefficient includes a plurality of attenuation coefficients. The low frequency portion corresponds to at least one damping coefficient, the high frequency portion corresponds to at least one damping coefficient, and the damping coefficient corresponding to the low frequency portion is smaller than the damping coefficient corresponding to the high frequency portion.

  In some embodiments, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

  The energy of the downmix signal can be calculated by using the energy of the first channel signal and the energy of the second channel signal, and the calculation process can be simplified without using the downmix signal itself.

  The above is a detailed description of the encoding method in the embodiment of the present application with reference to FIG. The following describes the decoding method in the embodiment of this application with reference to FIG. 7. It should be understood that the decoding method of FIG. 7 corresponds to the encoding method of FIG. For the sake of brevity, repeated explanations are appropriately omitted below.

  FIG. 7 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of this application. The method of FIG. 7 may be performed by a decoder-side device or decoder. The method of FIG. 7 specifically includes the following steps.

  710. Get the bitstream.

  720. Downmix signal of the first channel signal and the second channel signal in the multi-channel signal, the initial reverberation gain parameter of the first channel signal and the second channel signal, and of the first channel signal and the second channel signal The identification information is determined based on the bitstream, and the identification information is used to indicate the channel signal in the first channel signal and the second channel signal whose initial reverberation gain parameter needs to be adjusted. .

  730. A channel signal in the first channel signal and the second channel signal for which the initial reverberation gain parameter needs to be adjusted is determined as the target channel signal based on the identification information.

  740. Adjust the initial reverberation gain parameter of the target channel signal.

  In this application, the identification information can be used to determine the channel signal whose initial reverberation gain parameter needs to be adjusted, and also the initial reverberation of the channel signal before reverberation processing is performed on the channel signal. The gain parameter is adjusted, which improves the quality of the channel signal obtained after reverberation processing.

  Optionally, in one embodiment, adjusting the initial reverberation gain parameter of the target channel signal includes determining the target attenuation coefficient and adjusting the target attenuation coefficient to obtain the target reverberation gain parameter of the target channel signal. Adjusting the initial reverberation gain parameter of the target channel signal based on.

  The initial reverberation gain parameter of the channel signal can be flexibly adjusted based on the magnitude of the correlation between the channel signal and the downmix signal by using the attenuation coefficient.

  When determining the damping coefficient, the decoder side may determine the preset damping coefficient as the target damping coefficient. Alternatively, the decoder side directly adjusts the initial reverberation gain parameter of the target channel signal based on the preset attenuation coefficient.

  By presetting the damping coefficient, the process of determining the target damping coefficient can be simplified, thereby improving the decoding efficiency.

  In some embodiments, the decoder side may obtain the target attenuation coefficient from a bitstream of multiple channel signals, ie, obtain the target attenuation coefficient by decoding the bitstream of multiple channel signals. Good. In this case, the decoder side has already determined the target attenuation coefficient, and the target attenuation coefficient is encoded to obtain the bitstream and transmit it to the decoder side. In this way, the decoder side no longer needs to calculate the target attenuation coefficient, but directly decodes the bitstream to obtain the target attenuation coefficient.

  If the bitstream includes a target attenuation coefficient, the target attenuation coefficient may be obtained directly from the bitstream, and the process of determining the target attenuation coefficient can also be simplified, thereby decoding Efficiency is improved.

  Optionally, in one embodiment, the step of determining the target attenuation coefficient comprises, in particular, obtaining an inter-channel level difference between the first channel signal and the second channel signal from the bitstream. Determining the target attenuation coefficient based on the inter-channel level difference, or the target attenuation coefficient based on the inter-channel level difference and the downmix signal.

  The target attenuation coefficient can be more flexibly and accurately determined based on the inter-channel level difference, the downmix signal, etc. so that the initial reverberation parameter of the channel signal can be adjusted more accurately based on the attenuation coefficient.

  Specifically, when the level difference between channels is relatively large, the difference between the first channel signal and the second channel signal is relatively large, and the difference between the first channel signal and the second channel signal is The correlation between may be considered relatively small. In this case, a damping coefficient having a relatively large value may be determined as the target damping coefficient.

  In addition, if the target attenuation coefficient is determined based on the downmix signal, the target attenuation coefficient may be determined by using the periodicity and harmonics of the downmix signal. For example, when the periodicity or harmonics of the downmix signal is good, the difference between the first channel signal and the second channel signal is relatively small, and the first channel signal and the second channel signal The correlation between and may be considered to be relatively large. In this case, a damping coefficient having a relatively small value may be determined as the target damping coefficient.

  Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the target channel signal, and any subband has one attenuation factor. It corresponds only to the coefficient. For example, each of the first channel signal and the second channel signal may include a plurality of subbands, and a plurality of adjacent subbands may correspond to one attenuation coefficient.

  In addition, when the target damping coefficient includes a plurality of damping coefficients, the reverberation gain parameter can be adjusted more flexibly based on the target damping coefficient.

  In some other embodiments, the target channel signal comprises a first frequency band and a second frequency band, and the attenuation factors corresponding to subbands within the first frequency band are within the second frequency band. It is less than or equal to the attenuation coefficient corresponding to the subband, and the frequency of the first frequency band is smaller than the frequency of the second frequency band.

  The reverberation gain parameters for the high and low frequency subbands can be adjusted to different degrees by setting different size attenuation factors for the reverberation gain parameters for the high and low frequency subbands. In addition, a better processing effect can be obtained during the reverberation processing.

  For example, the frequency band in which the target channel signal is located includes a low frequency part and a high frequency part, and the target attenuation coefficient includes a plurality of attenuation coefficients. The low frequency portion corresponds to at least one damping coefficient, the high frequency portion corresponds to at least one damping coefficient, and the damping coefficient corresponding to the low frequency portion is smaller than the damping coefficient corresponding to the high frequency portion.

  The above is a detailed description of the encoding method and the decoding method in the embodiment of the present application with reference to FIGS. 3 to 7. The following describes the encoder and decoder in the embodiment of the present application with reference to FIGS. 8 to 13. It should be understood that the encoder and decoder in FIGS. 8 to 13 can perform the steps performed by the encoder and decoder in the encoding and decoding methods in the embodiments of this application. For the sake of brevity, repeated explanations are appropriately omitted below.

FIG. 8 is a schematic block diagram of an encoder according to an embodiment of this application. The encoder 800 in FIG.
A processing unit 810 configured to determine a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal. ,
The processing unit 810 includes a first channel signal based on the correlation between the first channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter. And a processing unit 810, further configured to determine a target reverberation gain parameter of the second channel signal,
Quantize the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter, and the quantized first channel signal and the quantized second channel signal into a bitstream. An encoding unit 820 configured to write,
including.

  Encoder 800 may correspond to the multi-channel signal encoding method in FIG. 3, and encoder 800 may perform the multi-channel signal encoding method in FIG.

  In this application, the correlation between the channel signal and the downmix signal is considered when the target reverberation gain parameter of the channel signal is determined. In this way, a better processing effect can be obtained when the reverberation processing is performed on the channel signal based on the target reverberation gain parameter, which improves the quality of the channel signal obtained after the reverberation processing.

  Optionally, in one embodiment, the processing unit 810 is specifically based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal. Is configured to determine the target attenuation coefficient and adjust the initial reverberation gain parameter based on the target attenuation coefficient to obtain the target reverberation gain parameter.

  Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the processing unit 810 specifically includes the first of the plurality of frequency bins. Determine a difference value between the energy of the channel signal and the energy of the downmix signal and between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins, and based on the difference value, the target attenuation It is configured to determine the coefficient.

  Optionally, in one embodiment, the processing unit 810 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, A difference value of 1 is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, the processing unit 810 Configured to determine a second difference value between the energy of the channel signal and the energy of the downmix signal, the second difference value being the energy of the first channel signal and the downmix signal in the plurality of frequency bins. , And the processing unit 810 determines a target damping coefficient based on a ratio between the first difference value and the second difference value. Configured to determine.

  Optionally, in one embodiment, prior to determining the target damping factor based on the difference value, processing unit 810 is more specifically configured to determine that the difference value is greater than a preset threshold. It

  Optionally, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

  Optionally, in one embodiment, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the plurality of channel signals, and any subband is a single It corresponds only to the damping coefficient.

FIG. 9 is a schematic block diagram of an encoder according to an embodiment of this application. The encoder 900 in FIG. 9 is
A processing unit 910 configured to determine a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal. ,
The processing unit 910 includes a first channel signal and a second channel signal based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal. Of the first channel signal and the second channel signal, the identification information of which is used to indicate the channel signal of which the initial reverberation gain parameter needs to be adjusted. A processing unit 910,
Quantize the first channel signal and the second channel signal based on the downmix signal, the initial reverberation gain parameter, and the identification information, and the quantized first channel signal and the quantized second channel signal An encoding unit 920 configured to write
including.

  In this application, the channel signal whose initial reverberation gain parameter needs to be adjusted can be determined based on the correlation between the channel signal and the downmix signal, so that the decoder side first After adjusting the initial reverberation gain parameters of some channel signals, reverberation processing can be performed on these channel signals, which can improve the quality of the channel signal obtained after the reverberation processing.

  It should be understood that the encoder 900 may correspond to the multi-channel signal encoding method in FIG. 6, and the encoder 900 may perform the multi-channel signal encoding method in FIG.

  Optionally, in one embodiment, the processing unit 910 specifically includes the correlation between the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and the downmix signal. It is configured to determine the identification information of the first channel signal and the second channel signal based on the correlation with the energy.

  Optionally, in one embodiment, the processing unit 910 specifically determines a first difference value and a second difference value, the first difference value being the first channel in the plurality of frequency bins. The sum of the absolute values of the difference values between the energy of the signal and the energy of the downmix signal, the second difference value of the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. Is the sum of the absolute values of the difference values between, and the processing unit 910 determines the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value. Specially composed.

  Optionally, in one embodiment, the processing unit 910 specifically determines the larger difference value of the first difference value and the second difference value as the target difference value and based on the target difference value. And the identification information is specifically used to indicate the channel signal corresponding to the target difference value, and the channel signal corresponding to the target difference value requires adjustment of its initial reverberation gain parameter. Is specifically configured to be a channel signal.

  Optionally, in one embodiment, processing unit 910 more specifically determines a target attenuation coefficient based on the first difference value and the second difference value, the target attenuation coefficient being the target channel signal. Used to adjust the initial reverberation gain parameter, the processing unit 910 is further specifically configured to quantize the target attenuation coefficient and write the quantized target attenuation coefficient to the bitstream.

  Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the target channel signal, and any subband has one attenuation factor. It corresponds only to the coefficient.

  Optionally, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

FIG. 10 is a schematic block diagram of a decoder according to an embodiment of this application. The decoder 1000 in FIG.
An acquisition unit 1010 configured to acquire the bitstream,
Downmix signal of the first channel signal and the second channel signal in the multi-channel signal, the initial reverberation gain parameter of the first channel signal and the second channel signal, and of the first channel signal and the second channel signal A processing unit 1020 configured to determine the identification information based on the bitstream, the identification information being in the first channel signal and the second channel signal and requiring adjustment of its initial reverberation gain parameter. A processing unit used to represent a channel signal,
Equipped with
The processing unit 1020 is further configured to determine, as the target channel signal, a channel signal in the first channel signal and the second channel signal whose initial reverberation gain parameter needs to be adjusted based on the identification information. Is
The processing unit 1020 is further configured to adjust the initial reverberation gain parameter of the target channel signal.

  In this application, the identification information can be used to determine the channel signal whose initial reverberation gain parameter needs to be adjusted, and also the initial reverberation of the channel signal before reverberation processing is performed on the channel signal. The gain parameter is adjusted, which improves the quality of the channel signal obtained after reverberation processing.

  It should be understood that the decoder 1000 may correspond to the multi-channel signal decoding method in FIG. 7, and the decoder 1000 may perform the multi-channel signal decoding method in FIG.

  Optionally, in one embodiment, processing unit 1020 specifically determines the target attenuation coefficient and adjusts the initial reverberation gain parameter of the target channel signal based on the target attenuation coefficient to adjust the target channel signal It is configured to obtain the target reverberation gain parameter.

  Optionally, in one embodiment, the processing unit 1020 is specifically configured to determine the preset damping coefficient as the target damping coefficient.

  Optionally, in one embodiment, processing unit 1020 is specifically configured to obtain the target damping factor based on the bitstream.

  Optionally, in one embodiment, the processing unit 1020 specifically obtains the inter-channel level difference between the first channel signal and the second channel signal from the bitstream and determines the inter-channel level difference. Is configured to determine the target attenuation coefficient based on, or the target attenuation coefficient is determined based on the inter-channel level difference and the downmix signal.

  Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the target channel signal, and any subband has one attenuation factor. It corresponds only to the coefficient.

FIG. 11 is a schematic block diagram of an encoder according to an embodiment of this application. The encoder 1100 in FIG.
A memory 1110 configured to store the program,
A processor 1120 configured to execute the program,
When the program is executed, the processor 1120 includes a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal. The first channel signal and the downmix signal, based on the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter. The target reverberation gain parameter of the second channel signal is determined, and the first channel signal and the second channel signal are quantized based on the downmix signal and the target reverberation gain parameter, and the quantized first channel signal is quantized. And configured to write the quantized second channel signal to the bitstream.

  Encoder 1100 may correspond to the multi-channel signal encoding method in FIG. 3, and encoder 1100 may perform the multi-channel signal encoding method in FIG.

  In this application, the correlation between the channel signal and the downmix signal is considered when the target reverberation gain parameter of the channel signal is determined. In this way, a better processing effect can be obtained when the reverberation processing is performed on the channel signal based on the target reverberation gain parameter, which improves the quality of the channel signal obtained after the reverberation processing.

  Optionally, in one embodiment, the processor 1120 is specifically based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal. It is configured to determine the target attenuation coefficient and adjust the initial reverberation gain parameter based on the target attenuation coefficient to obtain the target reverberation gain parameter.

  Optionally, in one embodiment, each of the first channel signal and the second channel signal includes a plurality of frequency bins, and the processor 1120 specifically includes the first channel in the plurality of frequency bins. Determine a difference value between the energy of the signal and the energy of the downmix signal and between the energy of the second channel signal and the energy of the downmix signal in a plurality of frequency bins, and based on the difference value, a target attenuation coefficient Is configured to determine.

  Optionally, in one embodiment, the processor 1120 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, the first The difference value of is used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins, and the processor 1120 determines that the second channel signal Is configured to determine a second difference value between the energy of the downmix signal and the energy of the downmix signal, the second difference value being the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins. Used to indicate the sum of the absolute values of the difference values between and, and the processor 1120 determines a target damping coefficient based on the ratio between the first difference value and the second difference value. To be configured.

  Optionally, in one embodiment, prior to determining the target damping factor based on the difference value, processor 1120 is more specifically configured to determine that the difference value is greater than a preset threshold. .

  Optionally, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

  Optionally, in one embodiment, the target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the plurality of channel signals, and any subband is a single It corresponds only to the damping coefficient.

FIG. 12 is a schematic block diagram of an encoder according to an embodiment of this application. The encoder 1200 in FIG. 12 is
A memory 1210 configured to store the program,
A processor 1220 configured to execute the program,
Including a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal when the program is executed. Along with determining, based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, the first channel signal and the second channel signal Configured to determine identification information, the identification information being used to indicate a channel signal in the first channel signal and the second channel signal for which its initial reverberation gain parameter needs to be adjusted, 1220 is a first channel signal and a second channel based on the downmix signal, the initial reverberation gain parameter, and the identification information. No. The quantized, and the second channel signal the first channel signal and the quantization are quantized to write into a bit stream.

  In this application, the channel signal whose initial reverberation gain parameter needs to be adjusted can be determined based on the correlation between the channel signal and the downmix signal, so that the decoder side first After adjusting the initial reverberation gain parameters of some channel signals, reverberation processing can be performed on these channel signals, which can improve the quality of the channel signal obtained after the reverberation processing.

  It should be understood that encoder 1200 may support the multi-channel signal encoding method in FIG. 6 and encoder 1200 may perform the multi-channel signal encoding method in FIG.

  Optionally, in one embodiment, the processor 1220 is specifically configured to specifically correlate the energy of the first channel signal and the energy of the downmix signal and the energy of the second channel signal and the energy of the downmix signal. And configured to determine identification information of the first channel signal and the second channel signal based on a correlation between and.

  Optionally, in one embodiment, the processor 1220 is specifically configured to determine a first difference value and a second difference value, the first difference value being the first of the plurality of frequency bins. 1 is the sum of the absolute value of the difference value between the energy of the channel signal and the energy of the downmix signal, the second difference value is the energy of the second channel signal and the downmix signal in a plurality of frequency bins The sum of the absolute values of the difference values between the energy and the processor 1220 determines the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value. Is configured as follows.

  Optionally, in one embodiment, the processor 1220 specifically determines the larger difference value in the first difference value and the second difference value as the target difference value and based on the target difference value. The identification information is configured to determine identification information, and the identification information is specifically used to indicate a channel signal corresponding to the target difference value, and the channel signal corresponding to the target difference value has its initial reverberation gain parameter This is the channel signal that needs to be adjusted.

  Optionally, in one embodiment, the processor 1220 is more specifically configured to determine a target damping coefficient based on the first difference value and the second difference value, the target damping coefficient being the target damping coefficient. Used to adjust the initial reverberation gain parameter of the channel signal, the processor 1220 is configured to quantize the target attenuation coefficient and write the quantized target attenuation coefficient to the bitstream.

  Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the target channel signal, and any subband has one attenuation factor. It corresponds only to the coefficient.

  Optionally, in one embodiment, the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.

FIG. 13 is a schematic block diagram of a decoder according to an embodiment of this application. The decoder 1300 in FIG.
A memory 1310 configured to store the program,
A processor 1320 configured to execute the program,
When the program is executed, the processor 1320 obtains a bitstream, downmix signal of the first channel signal and the second channel signal in the multi-channel signal, the first channel signal and the second channel signal. The initial reverberation gain parameter of the signal, and the identification information of the first channel signal and the second channel signal is configured to be determined based on the bitstream, the identification information, the first channel signal and the second channel signal. And used to indicate the channel signal whose initial reverberation gain parameter needs to be adjusted, the processor 1320 determines whether the first channel signal and the second channel signal are The channel signal that requires adjustment of the initial reverberation gain parameter is determined as the target channel signal, and Configured to adjust the initial reverberation gain parameter Le signal.

  In this application, the identification information can be used to determine the channel signal whose initial reverberation gain parameter needs to be adjusted, and also the initial reverberation of the channel signal before reverberation processing is performed on the channel signal. The gain parameter is adjusted, which improves the quality of the channel signal obtained after reverberation processing.

  It should be understood that the decoder 1300 may correspond to the multi-channel signal decoding method in FIG. 7, and the decoder 1300 may perform the multi-channel signal decoding method in FIG.

  Optionally, in one embodiment, the processor 1320 specifically determines the target attenuation coefficient and adjusts the initial reverberation gain parameter of the target channel signal based on the target attenuation coefficient to target the target channel signal. It is configured to obtain a reverberation gain parameter.

  Optionally, in one embodiment, the processor 1320 is specifically configured to determine the preset damping factor as the target damping factor.

  Optionally, in one embodiment, the processor 1320 is specifically configured to obtain the target damping factor based on the bitstream.

  Optionally, in one embodiment, the processor 1320 specifically obtains the inter-channel level difference between the first channel signal and the second channel signal from the bitstream and determines the inter-channel level difference. The target attenuation coefficient is determined based on the inter-channel level difference and the downmix signal.

  Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the target channel signal, and any subband has one attenuation factor. It corresponds only to the coefficient.

  As one of ordinary skill in the art will appreciate, electronic hardware or a combination of computer software and electronic hardware, in combination with the example units and algorithm steps described in the embodiments disclosed herein. Embodiments may be implemented according to. Whether the function is performed by hardware or software depends on the particular application and the design constraints of the technical solution. Persons skilled in the art may use different methods to implement the functions described for each particular application, but their implementation should not be considered beyond the scope of this application.

  As will be clearly understood by those skilled in the art, for convenience and brief description, please refer to the corresponding processes in the above-described method embodiments for the detailed working process of the above-mentioned system, equipment and unit. Therefore, it will not be described in detail again here.

  It should be understood that in some embodiments provided in this application, the disclosed systems, devices, and methods may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the unit division is merely a logical function division, and may be another division in actual implementation. For example, multiple units or components may be combined or integrated into other systems, or some features may be ignored or not implemented. Also, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented by using several interfaces. Indirect couplings or communication connections between devices or units may be implemented in electronic, mechanical or other forms.

  Units described as separate parts may or may not be physically separate, and parts shown as units may or may not be physical units. Well, it may be located in one location, or it may be distributed over multiple network units. Some or all of the units may be selected based on the actual requirements to achieve the goals of the solution of the embodiment.

  Also, the functional units in the embodiments of this application may be combined into one processing unit, or each of the units may physically exist alone, or two or more units may be one unit. May be incorporated into.

  If the function is implemented in the form of a software functional unit and sold or used as a stand-alone product, the function may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application, or the part contributing to the prior art or part of the technical solution may be implemented in the form of a software product. The computer software product is stored on a storage medium and is a computer device (such as a personal computer, server, network device, etc.) to perform all or some of the steps of the methods described in the embodiments of this application. Good instructions). The storage medium is any medium that can store the program code, for example, a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (Random Access Memory, RAM), magnetic disk, or optical disk.

  The preceding description is merely specific implementations of this application and is not intended to limit the scope of protection of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be limited to the protection scope of the claims.

800 encoder
810 processing unit
820 encoding unit
900 encoder
910 Processing unit
920 encoding unit
1000 decryptor
1010 Acquisition Unit
1020 processing unit
1100 encoder
1110 memory
1120 processor
1200 encoder
1210 memory
1220 processor
1300 encoder
1310 memory
1320 processor

The correlation between the first channel signal, the second channel signal, and the downmix signal can be conveniently measured by using the energy of the channel signal, that is, the energy of the channel signal and the downmix signal. The target damping coefficient can be conveniently determined by comparing the difference between the energy. Specifically, when the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal is relatively large (greater than a predetermined threshold value), the first The correlation between the channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal may be considered to be relatively weak. In this case, a relatively large target damping coefficient can be determined. However, if the difference between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal is relatively small (less than a predetermined threshold), then the first channel signal and The correlation between the downmix signal and the correlation between the second channel signal and the downmix signal may be considered to be relatively strong . In this case, a relatively small target damping coefficient can be determined.

With respect to the first aspect, in some implementations of the first aspect, between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and the second in the plurality of frequency bins. The step of determining the difference value between the energy of the channel signal and the energy of the downmix signal is the step of determining the first difference value between the energy of the first channel signal and the energy of the downmix signal. And the first difference value indicates the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins , step, and the energy of the second channel signal. And a second difference value between the energy of the downmix signal and the second mix value in the plurality of frequency bins. Indicates the sum of the absolute value of the difference between the energy of the energy and the downmix signal of the channel signal, and a step, also, the step of determining the target damping coefficient based on the difference value, the first difference value And determining a target damping coefficient based on a ratio between the second difference value and the second difference value.

With respect to the first aspect, in some implementations of the first aspect, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the multi-channel signal. Also, any subband corresponds to only one attenuation coefficient.

According to a second aspect, there is provided a multi-channel signal coding method , the method comprising: a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, a first channel signal and a second channel signal. Determining the initial reverberation gain parameter of the channel signal, the first channel based on the correlation between the first channel signal and the downmix signal and the second channel signal and the downmix signal; The step of determining the identification information of the signal and the second channel signal, the identification information, the channel signal in the first channel signal and the second channel signal and its initial reverberation gain parameter needs to be adjusted shown, steps and, the downmix signal, initial reverberation gain parameter, and the first channel signal and second channel signal based on the identification information Quantizing the signal and writing the quantized first channel signal and the quantized second channel signal to a bitstream.

In connection with the second aspect, in some implementations of the second aspect, the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value. The step of determining is a step of determining the larger difference value in the first difference value and the second difference value as the target difference value, and a step of determining the identification information based on the target difference value, the identification information there shows a channel signal corresponding to the target differential value, the channel signal corresponding to the target differential value, a channel signal it is necessary to adjust the initial reverberation gain parameter, and a step.

According to a third aspect, there is provided a multi-channel signal decoding method, the method comprising: obtaining a bitstream; down-mixing a first channel signal and a second channel signal in the multi-channel signal; A step of determining the initial reverberation gain parameters of the first channel signal and the second channel signal and the identification information of the first channel signal and the second channel signal based on the bitstream, wherein the identification information is the first Of the channel signal and the second channel signal of which the initial reverberation gain parameter needs to be adjusted , and, based on the identification information, the first channel signal and the second channel signal, And determining the channel signal whose initial reverberation gain parameter needs to be adjusted as the target channel signal. And adjusting the initial reverberation gain parameter of the target channel signals.

The target attenuation coefficient can be determined more flexibly and accurately based on inter-channel level difference, downmix signal, etc. so that the initial reverberation gain parameter of the channel signal can be adjusted more accurately based on the attenuation coefficient. .

According to a sixth aspect, a decoder is provided, the decoder including a module or unit configured to perform the method in the third aspect or various implementations of the third aspect.

3 is a schematic flowchart for encoding a left channel signal and a right channel signal in the related art. 3 is a schematic flowchart for decoding a left channel signal and a right channel signal in the related art. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal encoding method according to an embodiment of this application. 3 is a schematic flowchart of a multi-channel signal decoding method according to an embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the decoder concerning one Embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the encoder concerning one Embodiment of this application. It is a schematic block diagram of the decoder concerning one Embodiment of this application.

230. An uncorrelated signal is obtained based on the downmix signal and the spatial parameter of the current frame .

Optionally, in one embodiment, between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. Is a step of determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, the first difference value is a plurality of frequencies. A step between the energy of the second channel signal and the energy of the downmix signal showing the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the bin. Determining the difference value of 2 wherein the second difference value is the energy of the second channel signal in the plurality of frequency bins. Indicates the sum of the absolute value of the difference between the energy of over downmix signal, comprises steps and, and determining a target damping coefficient based on the first difference value and the second difference value.

For example, in the case (the M 0.5 to 1) energy M of the difference value is the first channel signal between the energy of the energy and the down-mix signal of the first channel signal is greater than times, first The difference value between the energy of the channel signal and the energy of the downmix signal may be considered to be greater than a preset threshold. In this case, the preset threshold is M times the energy of the first channel signal. Alternatively, when the ratio of the difference value between the energy of the first channel signal and the energy of the downmix signal to the energy of the first channel signal is larger than M, the energy of the first channel signal and the downmix are mixed. The difference value between the signal and the energy may be considered to be greater than a preset threshold.

Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the multi-channel signal , and any subband has one attenuation factor. It corresponds only to the coefficient.

In practice, the encoder side may instead only decide whether the initial reverberation gain parameter of the channel signal needs to be adjusted. When it is necessary to adjust the initial reverberation gain parameter of the channel signal, the encoder side sends corresponding instruction information to the decoder side . After receiving the indication information, the decoder side adjusts the initial reverberation gain parameter of the channel signal.

620. Determining the identification information of the first channel signal and the second channel signal based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, The identification information indicates a channel signal in the first channel signal and the second channel signal, the initial reverberation gain parameter of which needs to be adjusted .

Specifically, the identification information may indicate that the first channel signal or the second channel signal is a channel signal whose initial reverberation gain parameter needs to be adjusted, or the first channel signal And the second channel signal is a channel signal whose initial reverberation gain parameter needs to be adjusted, or the reverberation gain parameter is adjusted for both the first channel signal and the second channel signal. It may indicate that there is no need to do so.

In this application, by determining the relationship between the preset threshold and the magnitude of the difference value between the energy of the channel signal and the energy of the downmix signal, the energy of the channel signal is significantly different from the energy of the downmix signal. Then, the channel signal can be determined as the channel signal whose initial reverberation gain parameter needs to be adjusted. Therefore, the decoder side can first adjust the initial reverberation gain parameter of the channel signal and then perform reverberation processing on the channel signal, thereby improving the quality of the channel signal obtained after the reverberation processing. You can

Optionally, the step of determining the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value, the first difference value and the second difference value. determining a larger difference value as the target differential value in, and determining the identification information based on the target differential value indicates the target channel signal identification information corresponding to the target differential value, the target differential value Is a channel signal whose initial reverberation gain parameter needs to be adjusted.

Specifically, in some embodiments, the sum of the absolute values of the difference values between the energy of the first channel signal or the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins is added. The step of determining the identification information of the first channel signal and the second channel signal based on the absolute value of the difference value between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins sum and generating a first identification information when greater than a preset threshold, indicating that the need to adjust the initial reverberation gain parameter of the first channel signal is the first identification information, the step And the sum of the absolute values of the differences between the energy of the second channel signal and the energy of the downmix signal in the multiple frequency bins is preset And generating the second identification information when larger than the value indicates that the need to adjust the initial reverberation gain parameters of the second channel signal is the second identification information, and a step.

By determining the relationship between the preset threshold and the magnitude of the difference value between the energy of the channel signal and the energy of the downmix signal, the initial of when the energy of the channel signal is significantly different from the energy of the downmix signal. The channel signal can be determined as the channel signal for which the reverberation gain parameter needs to be adjusted. Therefore, the decoder side can first adjust the initial reverberation gain parameter of the channel signal and then perform reverberation processing on the channel signal, thereby improving the quality of the channel signal obtained after the reverberation processing. You can

It should be understood that the identification information of the first channel signal and the second channel signal may be one piece of identification information or two pieces of identification information. For example, when it is necessary to adjust both the initial reverberation gain parameter of the first channel signal and the second channel signal, the identification information of the first channel signal and the second channel signal is one fragment of the identification information. And the identification information indicates that both the initial reverberation gain parameters of the first channel signal and the second channel signal need to be adjusted. Alternatively, the identification information of the first channel signal and the second channel signal, two fragments of the identification information, that is, each of the first identification information and the second identification information, the first identification information, It indicates that the initial reverberation gain parameter of the first channel signal needs to be adjusted, and the second identification information indicates that the initial reverberation gain parameter of the second channel signal needs to be adjusted . If the channel signal has no corresponding identification information, it indicates that the initial reverberation gain parameter of the channel signal does not need to be adjusted. That is, when the identification information includes only the first identification information, it is necessary to adjust the initial reverberation gain parameter of only the first channel signal in the first channel signal and the second channel signal.

720. Downmix signal of the first channel signal and the second channel signal in the multi-channel signal, the initial reverberation gain parameter of the first channel signal and the second channel signal, and of the first channel signal and the second channel signal Identification information is determined based on the bitstream, the identification information indicating a channel signal in the first channel signal and the second channel signal for which the initial reverberation gain parameter needs to be adjusted .

In some embodiments, the decoder side may obtain the target attenuation coefficient from a bitstream of multiple channel signals, ie, obtain the target attenuation coefficient by decoding the bitstream of multiple channel signals. Good. In this case, the encoder side has already determined the target attenuation coefficient, encodes the target attenuation coefficient, obtains a bit stream, and transmits it to the decoder side. In this way, the decoder side no longer needs to calculate the target attenuation coefficient, but directly decodes the bitstream to obtain the target attenuation coefficient.

The target attenuation coefficient can be determined more flexibly and accurately based on inter-channel level difference, downmix signal, etc. so that the initial reverberation gain parameter of the channel signal can be adjusted more accurately based on the attenuation coefficient. .

Optionally, in one embodiment, the processing unit 810 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, The difference value of 1 indicates the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins , and the processing unit 810 determines the energy of the second channel signal. And a second difference value between the energy of the downmix signal and the energy of the second channel signal in the plurality of frequency bins. It means the sum of the absolute value of the difference between, also the processing unit 810 is configured to determine the target damping coefficient based on a ratio between the first difference value and the second difference value.

Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the multi-channel signal , and any subband has one attenuation factor. It corresponds only to the coefficient.

FIG. 9 is a schematic block diagram of an encoder according to an embodiment of this application. The encoder 900 in FIG. 9 is
A processing unit 910 configured to determine a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal. ,
The processing unit 910 includes a first channel signal and a second channel signal based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal. of determining the identification information, identification information indicates a channel signal it is necessary to adjust the initial reverberation gain parameter a into a first channel signal and second channel signal, further configured to process Unit 910,
Quantize the first channel signal and the second channel signal based on the downmix signal, the initial reverberation gain parameter, and the identification information, and the quantized first channel signal and the quantized second channel signal An encoding unit 920 configured to write
including.

Optionally, in one embodiment, the processing unit 910 specifically determines the larger difference value of the first difference value and the second difference value as the target difference value and based on the target difference value. The identification information specifically determines the channel signal corresponding to the target difference value, and the channel signal corresponding to the target difference value is the channel signal whose initial reverberation gain parameter needs to be adjusted. Is specifically configured to be.

FIG. 10 is a schematic block diagram of a decoder according to an embodiment of this application. The decoder 1000 in FIG.
An acquisition unit 1010 configured to acquire the bitstream,
Downmix signal of the first channel signal and the second channel signal in the multi-channel signal, the initial reverberation gain parameter of the first channel signal and the second channel signal, and of the first channel signal and the second channel signal A processing unit 1020 configured to determine the identification information based on the bitstream, the identification information being in the first channel signal and the second channel signal and requiring adjustment of its initial reverberation gain parameter. A processing unit , which represents a channel signal,
Equipped with
The processing unit 1020 is further configured to determine, as the target channel signal, a channel signal in the first channel signal and the second channel signal whose initial reverberation gain parameter needs to be adjusted based on the identification information. Is
The processing unit 1020 is further configured to adjust the initial reverberation gain parameter of the target channel signal.

Optionally, in one embodiment, the processor 1120 is specifically configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, the first The difference value of the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins , and the processor 1120 determines the sum of the energy of the second channel signal and the energy of the down channel signal. Is configured to determine a second difference value between the energy of the mix signal, the second difference value between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. The sum of absolute values of the difference values is indicated, and the processor 1120 is also configured to determine the target damping coefficient based on the ratio between the first difference value and the second difference value.

Optionally, in one embodiment, the target attenuation factor comprises a plurality of attenuation factors, each of the plurality of attenuation factors corresponding to at least one subband of the multi-channel signal , and any subband has one attenuation factor. It corresponds only to the coefficient.

FIG. 12 is a schematic block diagram of an encoder according to an embodiment of this application. The encoder 1200 in FIG. 12 is
A memory 1210 configured to store the program,
A processor 1220 configured to execute the program,
Including a downmix signal of the first channel signal and the second channel signal in the multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal when the program is executed. Along with determining, based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, the first channel signal and the second channel signal is configured to determine the identification information, the identification information may be in a first channel signal and second channel signal indicates the channel signal it is necessary to adjust the initial reverberation gain parameter, the processor 1220, down Quantize first channel signal and second channel signal based on mix signal, initial reverberation gain parameter, and identification information Configured the second channel signal the first channel signal and the quantization are quantized to write into a bit stream.

Optionally, in one embodiment, the processor 1220 specifically determines the larger difference value in the first difference value and the second difference value as the target difference value and based on the target difference value. Configured to determine identification information, the identification information indicating a channel signal corresponding to the target difference value, the channel signal corresponding to the target difference value being the channel signal for which its initial reverberation gain parameter needs to be adjusted .

FIG. 13 is a schematic block diagram of a decoder according to an embodiment of this application. The decoder 1300 in FIG.
A memory 1310 configured to store the program,
A processor 1320 configured to execute the program,
When the program is executed, the processor 1320 obtains a bitstream, downmix signal of the first channel signal and the second channel signal in the multi-channel signal, the first channel signal and the second channel signal. The initial reverberation gain parameter of the signal, and the identification information of the first channel signal and the second channel signal is configured to be determined based on the bitstream, the identification information, the first channel signal and the second channel signal. And indicating the channel signal whose initial reverberation gain parameter needs to be adjusted , the processor 1320 determines, based on the identification information, that the initial reverberation gain parameter is in the first channel signal and the second channel signal. and it determines as a target channel signal channel signal needs to be adjusted, and the target channel signals initial residual Configured to adjust the gain parameter.

Claims (40)

Downmix signal of the first channel signal and the second channel signal in the multi-channel signal, determining the initial reverberation gain parameter of the first channel signal and the second channel signal,
Based on the correlation between the first channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter, the first channel signal And determining a target reverberation gain parameter for the second channel signal,
Quantizing the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter, the quantized first channel signal and the quantized second channel signal Writing to the bitstream,
A multi-channel signal encoding method including. Correlation between the first channel signal and the downmix signal, correlation between the second channel signal and the downmix signal, and the first channel signal based on the initial reverberation gain parameter and The step of determining a target reverberation gain parameter of the second channel signal comprises:
Determining a target attenuation coefficient based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal;
Adjusting the initial reverberation gain parameter based on the target attenuation coefficient to obtain the target reverberation gain parameter,
The method of claim 1, comprising: Each of the first channel signal and the second channel signal includes a plurality of frequency bins, the correlation between the first channel signal and the downmix signal and the second channel signal and the down Determining the target damping coefficient based on the correlation with the mixed signal,
Between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins Determining the difference value,
Determining the target damping coefficient based on the difference value,
The method of claim 2, comprising: Between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins The step of determining the difference value comprises
Determining a first difference value between the energy of the first channel signal and the energy of the downmix signal, the first difference value being the first difference value in the plurality of frequency bins. Used to indicate the sum of the absolute values of the difference values between the energy of the channel signal and the energy of the downmix signal;
Determining a second difference value between the energy of the second channel signal and the energy of the downmix signal, the second difference value being the second difference value in the plurality of frequency bins. Used to indicate the sum of the absolute values of the difference values between the energy of the channel signal and the energy of the downmix signal;
Including,
The step of determining the target damping coefficient based on the difference value,
4. The method of claim 3, comprising: determining the target damping coefficient based on a ratio between the first difference value and the second difference value. Prior to the step of determining the target damping coefficient based on the difference value, the method comprises:
The method according to claim 3 or 4, further comprising: determining that the difference value is greater than a preset threshold.   The method according to any one of claims 3 to 5, wherein the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal.   The target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the plurality of channel signals, any subband corresponds to only one attenuation coefficient, The method according to any one of Items 2 to 6. Downmix signal of the first channel signal and the second channel signal in the multi-channel signal, determining the initial reverberation gain parameter of the first channel signal and the second channel signal,
Based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, the first channel signal and the second channel signal Of identifying information, wherein the identifying information indicates a channel signal in the first channel signal and the second channel signal for which an initial reverberation gain parameter needs to be adjusted. The steps used, and
Quantized the first channel signal and the second channel signal based on the downmix signal, the initial reverberation gain parameter, and the identification information, the quantized first channel signal and quantized Writing the second channel signal to the bitstream,
A multi-channel signal encoding method including. Based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, the first channel signal and the second channel signal The step of determining the identification information of
The first channel based on the correlation between the energy of the first channel signal and the energy of the downmix signal and the correlation between the energy of the second channel signal and the energy of the downmix signal A signal and determining the identification information of the second channel signal,
9. The method of claim 8, including. The first channel based on the correlation between the energy of the first channel signal and the energy of the downmix signal and the correlation between the energy of the second channel signal and the energy of the downmix signal The step of determining the identification information of the signal and the second channel signal,
A step of determining a first difference value and a second difference value, wherein the first difference value is between energy of the first channel signal and energy of the downmix signal in a plurality of frequency bins. A sum of absolute values of difference values, wherein the second difference value is a sum of absolute values of difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins. There are steps,
Determining the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value,
10. The method of claim 9, comprising: The step of determining the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value,
A step of determining the larger difference value in the first difference value and the second difference value as a target difference value;
Determining the identification information based on the target difference value, wherein the identification information is specifically used to indicate a channel signal corresponding to the target difference value, and the identification information corresponding to the target difference value. The channel signal is a channel signal whose initial reverberation gain parameter needs to be adjusted,
11. The method of claim 10, comprising: The method is
Determining a target attenuation coefficient based on the first difference value and the second difference value, the target attenuation coefficient is used to adjust an initial reverberation gain parameter of the target channel signal, Steps,
Quantizing the target attenuation coefficient and writing the quantized target attenuation coefficient to the bitstream;
The method of claim 11, further comprising:   The target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the target channel signal, and any subband corresponds to only one attenuation coefficient. The method described in 12.   14. The method according to any one of claims 9 to 13, wherein the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal. Obtaining the bitstream,
A downmix signal of a first channel signal and a second channel signal in a multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal, and the first channel signal and the second Determining the identification information of the channel signal on the basis of the bitstream, wherein the identification information is in the first channel signal and the second channel signal and adjusts an initial reverberation gain parameter thereof. The steps used to indicate the required channel signal,
Based on the identification information, determining the channel signal as a target channel signal in the first channel signal and the second channel signal it is necessary to adjust the initial reverberation gain parameter in the second channel signal,
Adjusting the initial reverberation gain parameter of the target channel signal;
A multi-channel signal decoding method including. The step of adjusting the initial reverberation gain parameter of the target channel signal comprises:
Determining a target damping coefficient,
Adjusting the initial reverberation gain parameter of the target channel signal based on the target attenuation coefficient to obtain a target reverberation gain parameter of the target channel signal;
16. The method of claim 15, comprising: The step of determining the target damping coefficient comprises:
Determining a preset damping coefficient as the target damping coefficient,
17. The method of claim 16, comprising: The step of determining the target damping coefficient comprises:
Obtaining the target attenuation coefficient based on the bitstream,
17. The method of claim 16, comprising: The step of determining the target damping coefficient comprises:
Obtaining the inter-channel level difference between the first channel signal and the second channel signal from the bitstream,
Determining the target attenuation coefficient based on the level difference between the channels, or
Determining the target attenuation coefficient based on the level difference between the channels and the downmix signal;
17. The method of claim 16, comprising:   The target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the target channel signal, and any subband corresponds to only one attenuation coefficient. The method according to any one of 16 to 19. A processing unit configured to determine a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal. hand,
The processing unit, based on the correlation between the first channel signal and the downmix signal, the correlation between the second channel signal and the downmix signal, and the initial reverberation gain parameter, the A processing unit further configured to determine a target reverberation gain parameter of the first channel signal and the second channel signal;
Quantizing the first channel signal and the second channel signal based on the downmix signal and the target reverberation gain parameter, the quantized first channel signal and the quantized second channel signal An encoding unit configured to write
An encoder. The processing unit is
Determining a target attenuation coefficient based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal,
Adjusting the initial reverberation gain parameter based on the target attenuation coefficient to obtain the target reverberation gain parameter,
22. The encoder of claim 21, specially configured to: Each of the first channel signal and the second channel signal includes a plurality of frequency bins, the processing unit,
Between the energy of the first channel signal and the energy of the downmix signal in the plurality of frequency bins and between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins Determine the difference value,
Determining the target damping coefficient based on the difference value,
23. The encoder of claim 22, specifically configured as: The processing unit is
Particularly configured to determine a first difference value between the energy of the first channel signal and the energy of the downmix signal, the first difference value being the at the plurality of frequency bins. Used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal,
Particularly configured to determine a second difference value between the energy of the second channel signal and the energy of the downmix signal, the second difference value being the at the plurality of frequency bins. Used to indicate the sum of the absolute values of the difference values between the energy of the first channel signal and the energy of the downmix signal,
Particularly configured to determine the target damping coefficient based on a ratio between the first difference value and the second difference value,
The encoder according to claim 23. Before determining the target damping coefficient based on the difference value, the processing unit:
Determining that the difference value is greater than a preset threshold,
25. An encoder according to claim 23 or 24, further configured as:   The encoder according to any one of claims 23 to 25, wherein the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal. .   The target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the plurality of channel signals, any subband corresponds to only one attenuation coefficient, The encoder according to any one of Items 22 to 26. A processing unit configured to determine a downmix signal of a first channel signal and a second channel signal in a multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal. hand,
The processing unit, based on the correlation between the first channel signal and the downmix signal and the correlation between the second channel signal and the downmix signal, the first channel signal and the To determine the identification information of the second channel signal, the identification information indicating a channel signal in the first channel signal and the second channel signal, the initial reverberation gain parameter of which needs to be adjusted. And a processing unit further configured to:
Quantized the first channel signal and the second channel signal based on the downmix signal, the initial reverberation gain parameter, and the identification information, the quantized first channel signal and quantized An encoding unit configured to write the second channel signal to the bitstream,
An encoder. The processing unit is
The first channel based on the correlation between the energy of the first channel signal and the energy of the downmix signal and the correlation between the energy of the second channel signal and the energy of the downmix signal A signal and determining the identification information of the second channel signal,
29. The encoder of claim 28, specially configured to: The processing unit is
Determine a first difference value and a second difference value, the first difference value of the difference value between the energy of the first channel signal and the energy of the downmix signal in a plurality of frequency bins. Is a sum of absolute values, the second difference value is a sum of absolute values of difference values between the energy of the second channel signal and the energy of the downmix signal in the plurality of frequency bins,
Determining the identification information of the first channel signal and the second channel signal based on the first difference value and the second difference value,
30. The encoder of claim 29, specially configured to: The processing unit is
Determine the larger difference value in the first difference value and the second difference value as the target difference value,
Determining the identification information based on the target difference value, the identification information being used specifically to indicate a channel signal corresponding to the target difference value, the channel signal corresponding to the target difference value having an initial Is the channel signal for which the reverberation gain parameter needs to be adjusted,
31. The encoder of claim 30, specially configured to: The processing unit is
A target attenuation coefficient is determined based on the first difference value and the second difference value, the target attenuation coefficient is used to adjust an initial reverberation gain parameter of the target channel signal,
Quantizing the target attenuation coefficient and writing the quantized target attenuation coefficient to the bitstream;
32. The encoder of claim 31, further configured to:   The target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the target channel signal, and any subband corresponds to only one attenuation coefficient. The encoder according to 32.   The encoder according to any one of claims 29 to 33, wherein the energy of the downmix signal is determined based on the energy of the first channel signal and the energy of the second channel signal. . An acquisition unit configured to acquire the bitstream,
A downmix signal of a first channel signal and a second channel signal in a multi-channel signal, an initial reverberation gain parameter of the first channel signal and the second channel signal, and the first channel signal and the second Processing unit configured to determine the identification information of the channel signal of the first channel signal and the second channel signal, the processing unit being configured to determine the identification information of the first channel signal and the second channel signal. A processing unit used to indicate the channel signal for which the gain parameter needs to be adjusted, and
Equipped with
The processing unit determines, as the target channel signal, the channel signal in the first channel signal and the second channel signal, the initial reverberation gain parameter of which needs to be adjusted, based on the identification information. Is further configured as
The processing unit is further configured to adjust the initial reverberation gain parameter of the target channel signal,
Decoder. The processing unit is
Determine the target damping coefficient,
Adjusting the initial reverberation gain parameter of the target channel signal based on the target attenuation coefficient to obtain a target reverberation gain parameter of the target channel signal,
36. The decoder of claim 35, specially configured to: The processing unit is
Determining a preset damping coefficient as the target damping coefficient,
37. The decoder of claim 36 specially configured to: The processing unit is
Obtaining the target attenuation coefficient based on the bitstream,
37. The decoder of claim 36 specially configured to: The processing unit is
Obtaining an inter-channel level difference between the first channel signal and the second channel signal from the bitstream,
Determining the target damping coefficient based on the level difference between the channels, or
Determining the target attenuation coefficient based on the inter-channel level difference and the downmix signal,
37. The decoder of claim 36 specially configured to:   The target attenuation coefficient comprises a plurality of attenuation coefficients, each of the plurality of attenuation coefficients corresponds to at least one subband of the target channel signal, and any subband corresponds to only one attenuation coefficient. The decoder according to any one of 36 to 39.

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